1. Field of the Invention
The present invention relates to a substrate type antenna configured on a thin substrate.
2. Description of the Related Art
As this type of substrate type antenna of related art, there has been known a configuration which has a substrate made of a dielectric material, a loop-like first coupled-portion or joint pattern formed in a first substrate surface of the substrate and divided at one spot thereof, and a loop-like second coupled-portion or joint pattern formed in a second substrate surface of the substrate and divided at one spot thereof, and in which electrostatic capacitively-coupled and magnetic inductively-coupled states are formed between the first joint pattern and the second joint pattern (refer to, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-142666)). According to such a configuration, unlike a conventional case in which patterns are formed on the same plane, the electrostatic capacitively-coupled and magnetic inductively-coupled states between the patterns based on the substrate are greatly improved, and a high-frequency coupler excellent in characteristic as compared with the related art can easily be obtained.
Since the substrate type antenna of the related art was however based only on the concept of an antenna having one resonant frequency, it was not able to take full advantage of the effect of using a thin substrate.